CN111201735A

CN111201735A - Method and apparatus for determining transport block size in a communication or broadcast system

Info

Publication number: CN111201735A
Application number: CN201880065924.6A
Authority: CN
Inventors: 吕贞镐; 李晓镇; 朴成珍; 吴振荣
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-09-08
Filing date: 2018-09-06
Publication date: 2020-05-26
Anticipated expiration: 2038-09-06
Also published as: US11290204B2; AU2018327936B2; KR102420721B1; US20200213032A1; CN111201735B; AU2018327936A1; EP4195548A1; EP3664328A1; US20240204957A1; US20220286223A1; KR102559502B1; US12483372B2; CN116582229B; US11973717B2; EP3664328B1; CN116582229A; KR20220102602A; KR20190028253A; EP3965329B1; EP3664328A4

Abstract

The present disclosure relates to a communication technology that merges a 5G communication system supporting a higher data transmission rate than a 4G system with an IoT technology, and a system thereof. The present disclosure may be applied to smart services such as smart homes, smart buildings, smart cities, smart cars or networked cars, healthcare, digital education, retail, security and security related services, and the like, based on 5G communication technology and IoT related technologies. In the present invention, a method and apparatus for determining the size of a transport block in a communication or broadcast system is disclosed.

Description

Method and apparatus for determining transport block size in a communication or broadcast system

Technical Field

The present disclosure relates to a method and apparatus for determining a size of a transport block in a communication or broadcast system.

Background

In order to meet the wireless data service demand, which has increased since the commercialization of the 4G communication system, efforts have been made to develop an improved 5G communication system or a quasi 5G communication system. Therefore, the 5G communication system or the quasi-5G communication system is also referred to as a super 4G network communication system or a post-LTE system.

In order to achieve a high data transmission rate, it is being considered to implement a 5G communication system in a millimeter wave (mmWave) frequency band (e.g., 60GHz band). In the 5G communication system, techniques such as beamforming, massive MIMO, Full-scale MIMO (FD-MIMO), array antenna, analog beamforming, and massive antenna are being discussed as means for mitigating propagation path loss and increasing propagation transmission distance in the millimeter wave band.

In addition, the 5G communication system has developed technologies such as evolved small cell, advanced small cell, cloud radio Access Network (cloud RAN), ultra-dense Network, device-to-device (D2D) communication, wireless backhaul, mobile Network, cooperative communication, coordinated multipoint (CoMP), and interference cancellation to improve the system Network.

In addition, the 5G system has developed Advanced Coding Modulation (ACM) schemes such as Hybrid FSK and QAM modulation (FQAM) and Sliding Window Superposition Coding (SWSC), and advanced Access techniques such as filterbank Multi-Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA).

Meanwhile, the Internet has evolved from a person-oriented connection network in which people generate and consume information to an Internet of Things (IoT) in which distributed components such as objects exchange and process information. Internet of everything (IoE) technology has emerged, in which big data processing technology is combined with IoT technology through a connection with a cloud server or the like. In order to implement IoT, technical factors such as sensing technology, wired/wireless communication, network infrastructure, service interface technology, and security technology are required, and technologies such as sensor network, machine-to-machine (M2M) communication, Machine Type Communication (MTC), etc. for connection between objects have recently been studied. In an IoT environment, by collecting and analyzing data generated in connected objects, an intelligent Internet Technology (IT) service that creates new value for people's lives may be provided. IoT may be applied to fields such as smart homes, smart buildings, smart cities, smart cars, networked cars, smart grids, healthcare, smart appliances, or high-tech medical services through the convergence of traditional Information Technology (IT) and various industries.

Accordingly, various attempts have been made to communicate with the IoT network application 5G. For example, 5G communication technologies such as sensor networks, machine-to-machine (M2M) communication, and Machine Type Communication (MTC) are implemented by techniques of beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology may be an example of 5G technology and IoT technology convergence.

In communication and broadcast systems, link performance may be greatly degraded due to various types of channel noise, fading phenomena, and inter-symbol interference (ISI). Therefore, in order to realize high-speed digital communication and broadcasting systems requiring high data throughput and high reliability, such as high-speed digital communication and broadcasting systems for next-generation mobile communication, digital broadcasting, and mobile internet, it is necessary to develop a technique of removing noise, fading, and inter-symbol interference. As a study of noise removal, studies of error correction codes have been actively conducted recently, with the object of realizing a method of improving reliability of communication by efficiently reconstructing distortion of information.

Disclosure of Invention

Technical problem

The present disclosure provides a method and apparatus for determining a Transport Block Size (TBS), which is the size of a Transport Block (TB) by which data can be efficiently transmitted using characteristics of a Low Density Parity Check (LDPC) code.

Technical scheme

According to an aspect of the present disclosure, there is provided a method of identifying a Transport Block Size (TBS) by a terminal in a wireless communication system. The method comprises the following steps: receiving control information for scheduling from a base station; identifying a number of temporary information ratios based on the control information for scheduling; identifying a TBS based on the control information for scheduling and the number of temporary information bits; and decoding the received downlink data based on the identified TBS, wherein the TBS is a multiple of both 8 and a number of temporary Code Blocks (CBs) identified based on the control information for scheduling.

If the code rate identified based on the scheduling information is equal to or less than 0.25 and the number of temporary information bits is N, based on

Identifying the number of temporary CBs, if the code rate identified based on the scheduling information is greater than 0.25 and the number of temporary information bits is N greater than 8424, based on

The number of temporary CBs is identified.

According to another aspect of the present disclosure, a method of identifying a Transport Block Size (TBS) by a base station in a wireless communication system is provided. The method comprises the following steps: identifying control information for scheduling; transmitting control information for scheduling to a terminal; identifying a number of temporary information bits based on control information for scheduling; identifying a TBS based on the control information for scheduling and the number of temporary information bits; and transmitting downlink data based on the identified TBS, wherein the TBS is a multiple of both 8 and a number of temporary Code Blocks (CBs) identified based on control information for scheduling.

According to another aspect of the present disclosure, there is provided a terminal for identifying a Transport Block Size (TBS) in a wireless communication system. The terminal includes: a transceiver; and a controller configured to perform control to receive control information for scheduling from the base station, identify a number of temporary information bits based on the control information for scheduling, identify a TBS based on the control information for scheduling and the number of temporary information bits, and decode received downlink data based on the identified TBS, the controller being connected to the transceiver, wherein the TBS is a multiple of both a TBS 8 and a number of temporary Code Blocks (CBs) identified based on the control information for scheduling.

Advantageous effects of the invention

The present disclosure provides a method and apparatus for determining a TBs, which is the size of a TB, by minimizing the addition of unnecessary bits using the characteristics of an LDPC code, allocated resources, and a code rate, thereby efficiently transmitting and receiving data.

Drawings

Fig. 1 shows the structure of transmissions in the downlink time-frequency domain of an LTE or LTE-a system;

fig. 2 shows the structure of transmissions in the uplink time-frequency domain of an LTE or LTE-a system;

FIG. 3 shows a basic structure of a mother matrix (or basic graph) of an LDPC code;

fig. 4 is a block diagram showing a reception process of a terminal;

fig. 5 illustrates a method of segmenting a Transport Block (TB) into code blocks;

figure 6 is a flow chart illustrating operation of a base station and terminal implementing some embodiments of the present disclosure;

fig. 7 is a block diagram illustrating a structure of a terminal according to an embodiment of the present disclosure; and

fig. 8 is a block diagram illustrating a structure of a base station according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In describing exemplary embodiments of the present disclosure, descriptions related to technical contents that are well known in the art to which the present disclosure pertains and that are not directly related to the present disclosure will be omitted. Such omission of unnecessary description is intended to prevent obscuring and more clearly communicating the underlying ideas of the present disclosure.

For the same reason, in the drawings, some elements may be enlarged, omitted, or schematically shown. Further, the size of each element does not completely reflect the actual size. In the drawings, the same or corresponding elements have the same reference numerals.

Advantages and features of the present disclosure and the manner of attaining them will become apparent by reference to the following detailed description of embodiments when taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments set forth below, but may be embodied in various different forms. The following examples are provided solely for the purpose of complete disclosure and to inform those skilled in the art of the scope of the disclosure, and the disclosure is to be limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements.

Here, it should be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a computer usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block(s).

And each block of the flowchart illustrations may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

As used herein, a "unit" refers to a software element or a hardware element that performs a predetermined function, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC). However, the "unit" does not always have a meaning limited to software or hardware. A "unit" may be configured to be stored in an addressable storage medium or to execute one or more processors. Thus, a "unit" includes, for example, a software element, an object-oriented software element, a class element or task element, a process (process), a function, an attribute, a procedure (process), a subprogram, a segment of program code, a driver, firmware, microcode, circuitry, data, a database, a data structure, a table, an array, and a parameter. The elements and functions provided by a "unit" may be combined into a smaller number of elements, a "unit", or divided into a larger number of elements, a "unit". Further, the elements and "units" may be implemented to render one or more CPUs within a device or secure multimedia card. Also, in an embodiment, a "unit" may include one or more processors.

Wireless communication systems have been developed into Broadband wireless communication systems that provide High-speed and High-quality Packet Data services according to communication standards such as High-speed Packet Access (HSPA) of 3GPP, Long Term Evolution (LTE) or evolved universal terrestrial radio Access (E-UTRA), LTE-advanced (LTE-a), LTE-Pro, High-Rate Packet Data (HRPD) of 3GPP2, Ultra-Mobile Broadband (UMB), 802.16E of IEEE, and the like, in addition to voice-based services provided at an initial stage.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, a detailed description of known functions or configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear. Terms to be described below are terms defined in consideration of functions in the present disclosure, and may be different according to a user, a user intention, or a habit. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

Hereinafter, a Base Station (BS) is an entity that allocates resources to a terminal, and may be one of a enode B, an eNodeB, a Node B, a radio access unit, a base station controller, and a Node on a network. Terminals may include User Equipment (UE), Mobile Stations (MS), cellular phones, smart phones, computers, and multimedia systems capable of performing communication functions. In the present disclosure, Downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and Uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station.

Hereinafter, the embodiments of the present disclosure are described on the basis of an LTE or LTE-a system (hereinafter, referred to as an LTE system) by way of example, but the embodiments of the present disclosure may also be applied to other communication systems having a similar background or channel form. For example, the 5 th generation mobile communication technology (5G, new radio and NR) developed after LTE-a may be included therein. Embodiments of the present disclosure may be applied to other communication systems by modification, based on the determination of those skilled in the art, without departing from the scope of the present disclosure.

An LTE system, which is a representative example of a broadband wireless communication system, employs an Orthogonal Frequency Division Multiplexing (OFDM) scheme for a Downlink (DL) and a single carrier frequency division multiple access (SC-FDMA) scheme for an Uplink (UL). In the above-described multiple access scheme, time-frequency resources for carrying data or control information are allocated and operated in a manner that resource overlap is avoided, i.e., orthogonality is established between users in order to identify data or control information of each user.

When decoding fails in the initial transmission, the LTE system employs a hybrid automatic repeat request (HARQ) that retransmits (transmit) corresponding data in the physical layer. In the HARQ scheme, if the receiver cannot correctly decode data, the receiver transmits information (negative acknowledgement: NACK) informing the transmitter of decoding failure, so that the transmitter can retransmit corresponding data on the physical layer. The receiver improves data reception performance by combining data retransmitted by the transmitter with data whose decoding failed. In addition, if the receiver decodes the data correctly, the receiver transmits information reporting that the decoding was successfully performed (acknowledgement: ACK), so that the transmitter transmits new data.

Fig. 1 shows a basic structure of a time-frequency domain, which is a downlink radio resource region in an LTE system.

In fig. 1, the horizontal axis indicates the time domain and the vertical axis indicates the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol. One time slot 106 is formed by N_symbOne OFDM symbol 102 and one subframe 105 consists of 2 slots. The length of 1 slot is 0.5ms (milliseconds), and the length of 1 subframe is 1.0 ms. The radio frame 114 is a time domain interval consisting of 10 subframes. In the frequency domain, the smallest transmission unit is a subcarrier. The bandwidth of the whole system transmission band is composed of N in total_BWSub-carriers 104.

The basic unit of resources in the time-frequency domain is a Resource Element (RE)112, and tu may be indicated by an OFDM symbol index and a subcarrier index. Resource blocks (RBs or Physical Resource Blocks (PRBs)) 108 are defined by N in the time domain_symbA number of consecutive OFDM symbols 102 and N in the frequency domain_RBA number of consecutive sub-carriers 110. Thus, one RB 108 includes N_symb×N_RBAnd RE 112. Generally, the minimum transmission unit of data is an RB unit. Generally, in an LTE system, N_symb7 and N_RB＝12。N_BWProportional to the system transmission bandwidth. The data rate increases in proportion to the number of RBs scheduled in the terminal.

In the LTE system, 6 transmission bandwidths are defined and operated. In the case of a Frequency Division Duplex (FDD) system that divides downlink and uplink according to frequency, a downlink transmission bandwidth and an uplink transmission bandwidth may be different from each other. The channel bandwidth may indicate an RF bandwidth, which corresponds to a system transmission bandwidth. Table 1 provided below indicates the relationship between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, when the LTE system has a channel bandwidth of 10MHz, the transmission bandwidth may include 50 RBs.

[ Table 1]

Downlink Control Information (DCI) is transmitted within the first N OFDM symbols in a subframe. Typically, N ═ 1,2, 3. Therefore, N changes in every subframe according to the amount of control information that should be transmitted in the current subframe. The control information includes a control channel transmission interval indicator indicating how many OFDM symbols are used to transmit the control information, scheduling information of downlink data or uplink data, and a HARQ ACK/NACK signal.

In the LTE system, scheduling information of downlink data or uplink data is transmitted from a base station to a terminal through downlink control information. DCI is defined in various formats. The determined DCI format is applied and operated according to whether DCI is scheduling information (UL grant) for uplink data or scheduling information (DL grant) for downlink data, whether DCI is compact DCI having small-sized control information, whether DCI applies spatial multiplexing using multiple antennas, and whether DCI is DCI for controlling power. For example, DCI format 1 indicating scheduling control information (DL grant) for downlink data may be configured as at least one piece of information among at least the following control information.

-resource allocation type 0/1 flag: indicating whether the resource allocation type is type 0 or type 1. Type 0 applies a bitmap (bitmap) scheme, and resources are allocated in units of Resource Block Groups (RBGs). In the LTE system, a basic scheduling unit is a Resource Block (RB) represented by time domain resources and frequency domain resources, and in type 0, an RBG includes a plurality of RBs and is used as a basic scheduling unit. Type 1 allows predetermined RBs in the RBG to be allocated.

-resource block allocation: indicating the RBs allocated for data transmission. The resources represented are determined according to the system bandwidth and the resource allocation type.

Modulation and Coding Scheme (MCS): indicating the modulation scheme used for data transmission and the size of the transport block (i.e., the data to be transmitted).

-HARQ process number: indicating the process number of HARQ.

-New Data Indicator (New Data Indicator): indicating HARQ initial transmission or HARQ retransmission.

Redundancy Version (Redundancy Version, RV): indicating the redundancy version of HARQ.

Transmit Power Control (TPC) commands for Physical Uplink Control Channel (PUCCH): a transmission power control command for a PUCCH, which is an uplink control channel, is indicated.

The DCI is transmitted through a Physical Downlink Control Channel (PDCCH) or an enhanced PDCCH (epdcch) which is a downlink physical control channel via a channel coding and modulation process. Hereinafter, PDCCH transmission/reception or EPDCCH transmission/reception may be understood as DCI transmission/reception on PDCCH or EPDCCH. Hereinafter, such techniques may be applied to other channels.

In general, DCI is scrambled with a specific Radio Network Temporary Identifier (RNTI) (or terminal identifier) independently for each terminal, a Cyclic Redundancy Check (CRC) is added, and channel coding is performed, thereby configuring and transmitting each independent PDCCH. In the time region, the PDCCH is mapped and transmitted during a control channel transmission interval. The mapping position of the PDCCH in the frequency domain is determined by an Identifier (ID) of each terminal and is propagated to the entire system transmission band.

Downlink data is transmitted through a Physical Downlink Shared Channel (PDSCH), which is a physical downlink data channel. The PDSCH is transmitted after the control channel transmission interval, and detailed mapping information in the frequency region and scheduling information such as a modulation scheme may be known through DCI, which is transmitted through the PDCCH.

The base station may report a modulation scheme applied to a PDSCH to be transmitted to the terminal and a size of data to be transmitted (transport block size (TBS)) via an MCS formed of 5 bits in control information included in the DCI. The TBS corresponds to a size before channel coding for error correction (error correction) is applied to data (i.e., a transport block) to be transmitted by the base station.

Modulation schemes supported by the LTE system include Quadrature Phase Shift Keying (QPSK), 16 quadrature amplitude modulation (16QAM), and 64 QAM. The modulation orders correspond to 2, 4 and 6, respectively. That is, in QPSK modulation, the base station may transmit 2 bits per symbol, in 16QAM modulation, the base station may transmit 4 bits per symbol, and in 64QAM modulation, the base station may transmit 6 bits per symbol.

Fig. 2 shows a basic structure of a time-frequency domain, which is an uplink radio resource domain in an LTE system.

Referring to fig. 2, the horizontal axis indicates a time domain and the vertical axis indicates a frequency domain. The smallest transmission unit in the time domain is an SC-FDM symbol, and one slot 206 consists of N_symbOne SC-FDMA symbol 202. One subframe 205 includes two slots. The minimum transmission unit in the frequency domain is a subcarrier, and the entire system transmission band (transmission bandwidth) is composed of N in total_BWThe subcarriers 204. N is a radical of_BWWith a value proportional to the system transmission bandwidth.

A basic unit of resources in the time-frequency domain is a Resource Element (RE)212, and may be defined by an SC-FDMA symbol index and a subcarrier index. Resource Block (RB)208 is defined by N in the time domain_symbOne continuous SC-FDMA symbol and N in frequency domain_BWA number of consecutive sub-carriers. Thus, one RB is formed by N_symb×N_RBAnd RE. Generally, the smallest transmission unit of data or control information is an RB. The PUCCH is mapped to a frequency domain corresponding to 1 RB and may be transmitted during 1 subframe.

In the LTE system, a timing relationship of a PUCCH or a Physical Uplink Shared Channel (PUSCH) as an uplink physical channel through which HARQ ACK/NACK is transmitted is defined, wherein the HARQ ACK/NACK corresponds to a PDSCH as a physical channel for downlink data transmission or a PDCCH or an EPDCCH including a semi-persistent scheduling release (SPS release). For example, in an LTE system operating in an FDD manner, HARQ ACK/NACK corresponding to a PDSCH transmitted in an n-4 th subframe or a PDCCH or EPDCCH including SRS release is transmitted to a PUCCH or PUSCH in an n-th subframe.

In the LTE system, downlink HARQ employs an asynchronous HARQ scheme in which the time for retransmitting data is not fixed. That is, if the base station receives HARQ NACK feedback of data initially transmitted by the base station from the terminal, the base station freely determines a time point at which retransmission data is transmitted via a scheduling operation. For the HARQ operation, the terminal buffers data determined to be erroneous based on the result of decoding the received data and then combines the data with data retransmitted subsequently.

If the terminal receives the PDSCH including the downlink data transmitted from the base station through the subframe n, the terminal transmits uplink control information including HARQ ACK or NACK of the downlink data to the base station through the PUCCH or PUSCH in the subframe n + k. In this case, k is defined differently according to whether the LTE system adopts FDD or Time Division Duplex (TDD) and a configuration of its subframes. For example, in the case of the FDD LTE system, k is fixed to 4. Meanwhile, in case of the TDD LTE system, k may be changed according to a subframe configuration and a subframe number.

In the LTE system, unlike the downlink HARQ, the uplink HARQ employs a synchronous HARQ scheme in which a time point at which data is transmitted is fixed. That is, the uplink/downlink timing relationship between the PUSCH as a physical channel for uplink data transmission, the PDCCH as a downlink control channel preceding it, and the PHICH as a physical channel for transmitting downlink HARQ ACK/NACK corresponding to the PUSCH is fixed by the following rule.

If the terminal receives a PDCCH including uplink scheduling control information transmitted from the base station or a PHICH for transmitting downlink HARQ ACK/NACK in subframe n, the terminal transmits uplink data corresponding to the control information through a PUSCH in subframe n + k. At this time, k is defined differently according to whether the LTE system adopts FDD or TDD and its configuration. For example, in the case of the FDD LTE system, k is fixed to 4. Meanwhile, in case of the TDD LTE system, k may be changed according to a subframe configuration and a subframe number.

Further, if the terminal receives a PHICH carrying downlink HARQ ACK/NACK from the base station in subframe i, the PHICH corresponds to a PUSCH transmitted by the terminal in subframe (i-k). At this time, k is defined differently according to whether the LTE system adopts FDD or TDD and its configuration. For example, in the case of the FDD LTE system, k is fixed to 4. Meanwhile, in case of the TDD LTE system, k may be changed according to a subframe configuration and a subframe number.

Also, when data is transmitted through a plurality of carriers, k may be differently applied according to a TDD configuration of each carrier.

[ Table 2]

Table 2 above shows supportable DCI formats according to each transmission mode under the condition set by C-RNTI in 3GPP TS 36.213. The terminal assumes that there is a corresponding DCI format in a control region interval according to a preset transmission mode, and performs searching and decoding. For example, if transmission mode 8 is indicated to the terminal, the terminal searches for DCI format 1A in the common search space and the UE-specific search space, and searches for DCI format 2B only in the UE-specific search space.

The description of the wireless communication system is provided from the perspective of the LTE system, but the present disclosure is not limited to the LTE system and can be applied to various wireless communication systems such as NR, 5G, and the like. Further, if the present embodiment is applied to other wireless communication systems, k may be changed and applied to a system using a modulation scheme corresponding to FDD.

The present disclosure provides methods and apparatus for transmitting coded bits that can support various input lengths and code rates. Further, the present disclosure provides a method of configuring a base graph (base graph) of an LDPC code for data channel transmission, and a method and apparatus for partitioning a Transport Block (TB) using the LDPC code.

Subsequently, a Low Density Parity Check (LDPC) code will be described.

The LDPC code is one of linear block codes, and a process of determining a codeword satisfying a condition such as [ equation 1] below is included.

[ equation 1]

In [ equation 1]]In (1),

in [ equation 1]]Where H denotes a parity check matrix, C denotes a codeword, C_iRepresents the ith bit of the codeword, and N_ldpcIndicating the LDPC codeword length. Here, h_iRepresents the ith column of the parity check matrix (H).

The parity check matrix H includes N_ldpcColumn, said N_ldpcThe same number of bits as the LDPC codeword. [ equation 1]]Meaning the ith column (h) of the parity check matrix_i) And ith codeword bit c_iThe sum of the products of (a) is "0", so that the ith column (h)_i) And ith codeword bit c_iAnd (4) associating.

For parity check matrices used in communication and broadcasting systems, quasi-cyclic LDPC codes (QC-LDPC codes, or, hereinafter, QC-LDPC codes) that generally use quasi-cyclic (quasi _ cyclic) parity check matrices are frequently used for ease of implementation.

The QC-LDPC code is characterized by a parity check matrix including a 0 matrix (zero matrix) or a cyclic permutation matrix (permutation matrix) having a small square matrix form.

As follows [ equation 2]As shown in (a), a permutation matrix P of size ZXZ ═ P (P)_ij) Is defined.

[ equation 2]

In [ equation 2]]In, P_ij(0≤i,j<Z) is an element (entry) of the ith row and jth column of the matrix P. When 0 ≦ i for the above permutation matrix<On the basis of Z, it can be noted that P is a cyclic permutation matrix obtained by cyclically shifting each element of an identity matrix of size ZXZ to the right by i.

The parity check matrix H of the simplest QC-LDPC code can be indicated as shown in table 3 below.

[ equation 3]

If P is^-1Defined as a 0 matrix of size ZXZ, each index a of the cyclic permutation matrix or 0 matrix_ijHas one of the values { -1,0,1, 2. Further, it can be noted that [ equation 3]]The parity check matrix H of (2) is mzh-z-H-nZ in size because it has n column blocks and m row blocks.

In general, a binary matrix of size mXn obtained by replacing a cyclic permutation matrix and a 0 matrix in the parity check matrix of [ equation 3] above with 1 and 0 is determined as a mother matrix (or a basic diagram) of the parity check matrix, and an integer matrix (integer matrix) of size mXn obtained by selecting only an index of the cyclic permutation matrix or the 0 matrix is determined as an index matrix e (H) of the parity check matrix H, as shown in [ equation 4] below.

[ equation 4]

Meanwhile, the performance of the LDPC code may be determined according to the parity check matrix. Therefore, it is required to design an efficient parity check matrix of an LDPC code having excellent performance. In addition, LDPC encoding and decoding methods supporting various input lengths and code rates are required.

A method known as lifting (lifting) for efficient design of QC-LDPC codes is used. Lifting is a method of efficiently designing a very large parity check matrix by configuring a Z value determining the size of a cyclic permutation matrix or a 0 matrix from a given small mother matrix according to a specific rule. The conventional lifting method and the characteristics of the QC-LDPC code designed by the lifting are briefly described below.

If given LDPC code C₀The S QC-LDPC codes to be designed by the lifting method are C₁,C₂,...,C_k,...,C_S(similarly, for C_kFor example, k is more than or equal to 1 and less than or equal to S), QC-LDPC code C_kIs H_kAnd a value corresponding to the sizes of row blocks and column blocks of a permutation matrix included in the parity check matrix is Z_k。C₀Corresponding to having a mother matrix C₁,., and C_SMinimum LDPC code as parity check matrix, Z corresponding to size of row block and column block₀The value is 1, and for Z_k<Z_k+1For example, k is 0. ltoreq. S-1. For convenience, each code C_kParity check matrix H of_kIndex matrix E (H) with size m Pipeln_k))＝a_i,j ^(k)And the value { -1,0,1,2_kOne of-1 } is selected as each index a_i,j ^(k). The lifting comprises a step C₀→C₁→...→C_SAnd is characterized by Z_k+1＝q_k+1Z_k(q_k+1Is a positive integer, k ═ 0, 1.., S-1). If only C is due to the nature of the lifting process_SParity check matrix H of_SIs stored, the following [ equation 5] can be used according to the lifting method]Or [ equation 6]]To indicate all QC-LDPC codes C₀,C₁,...,C_S。

[ equation 5]

[ equation 6]

E(H_k)≡E(H_S)modZ_k

Equation 7 is the most general representation of the method.

[ equation 7]

P_i,j＝f(V_i,j,Z)

In [ equation 7]]Where f (x, y) is a predetermined function having x and y as input values. V_i,jCorresponds to the maximum LDPC code (e.g., C in the above description)_SCorresponding) element of ith row and jth column of the exponent matrix of the parity check matrix. P_ijIs corresponding to an LDPC code having a predetermined size (e.g., C in the above description)_kCorresponding) element of ith row and jth column of the exponent matrix of the parity check matrix, and Z is the size of row block and column block of the circulant matrix included in the parity check matrix of the corresponding LDPC code. Therefore, if V_i,jA parity check matrix for an LDPC code having a predetermined size may be defined.

In the description of the present disclosure to be provided later, the above symbols are named, defined, and used as follows.

[ definition 1]

E(H_S) Maximum index matrix

V_i,jMaximum index matrix element (and E (H)_S) Element (i, j) of (1) corresponds to)

The parity check matrix for the predetermined LDPC code may be indicated using the maximum exponent matrix or the maximum exponent matrix elements defined above.

In the next generation mobile communication system, there may be a plurality of the above-defined maximum exponent matrices in order to guarantee the best performance of code blocks having various lengths. For example, there may be M different maximum exponent matrices, which may be represented as the following table.

[ equation 8]

E(H_S)₁，E(H_S)₂，...，E(H_S)_M

There may be a plurality of maximum exponent matrix elements corresponding thereto, which may be represented as the following table.

[ equation 9]

(V_i，j)₁，(V_i，j)₂，...，(V_i，j)_M

In [ equation 9]]Medium, maximum index matrix element (V)_i,j)_mCorresponding to the maximum exponential matrix E (H)_S)_m(i, j) of (1). Hereinafter, in the definition of the parity check matrix for the LDPC code, the maximum exponent matrix of the above definition will be used and described. This can be applied in the same way as using the representation of the largest exponential matrix element.

The turbo code based code block segmentation and CRC addition method in the document of LTE TS 36.213 is cited below.

5.1.2 code block segmentation and code block CRC addition

The input bit sequence for code block segmentation is denoted b₀,b₁,b₂,b₃,...,b_B-1In which B is>0. If B is larger than the maximum code block length Z, segmentation is performed on the input bit sequence, adding an additional CRC sequence of L-24 bits to each code block. The maximum code block size is:

-Z＝6144.

if the number of padding bits is not 0, as calculated from the following, padding bits are added at the beginning of the first block.

Note that if B <40, the filler bits are directly added at the beginning of the code block.

At the input of the encoder, the padding bits should be set to < NULL >.

The total number of code blocks C is determined by the following steps:

for the case of C ≠ 0, the bits output from code block segmentation are denoted C_r0,c_r1,c_r2,c_r3,...,c_r(_Kr-1), wherein r is the code block number, and K_rIs the number of bits used for the code block number r.

The number of bits in each code block (applicable only for the case of C ≠ 0):

first division size K₊The minimum K satisfying C.K.gtoreq.B' in Table 5.1.3-3.

Number of padding bits: f ═ C₊·K₊+C_-·K--B′

According to a generator polynomial g_CRC24B(D) Subsection 5.1.1, sequence c_r0,c_r1,c_r2,c_r3,...,c_r(Kr-L-1)Is used to calculate the parity bit p_r0,p_r1,p_r2,...,p_r(L-1). For the CRC calculation, it is assumed that the pad bits, if any, have a value of 0.

Unlike the LTE system, the 5G and next generation communication systems use LDPC codes in data channels. Even in the case of applying the LDPC code, one transport block may be divided into a plurality of code blocks, and some of the code blocks may form one code block group. Further, the number of code blocks of the respective code block groups may be the same as each other or may have different values. Interleaving in units of bits may be applied to individual code blocks, groups of code blocks, or transport blocks.

Fig. 3 shows a basic structure of a mother matrix (or basic diagram) of an LDPC code.

In fig. 3, two basic structures of a basic diagram 300 of an LDPC code supporting data channel coding are basically supported by a next-generation mobile communication system. The first basic graph structure of the LDPC code is a matrix structure having a maximum vertical length 320 of 46 and a maximum horizontal length 318 of 68, and the second basic graph structure of the LDPC code is a matrix structure having a maximum vertical length 320 of 42 and a maximum horizontal length 318 of 52. The first basic graph structure of the LDPC code may support a code rate of 1/3 minimum to 8/9 maximum, and the second basic graph structure of the LDPC code may support a code rate of 1/5 minimum to 8/9 maximum.

Basically, the LDPC code may include 6 sub-matrix structures. The first sub-matrix structure 302 includes systematic bits. The second sub-matrix structure 304 is a square matrix and includes parity check bits. The third sub-matrix structure 306 is a zero matrix. The fourth sub-matrix structure 308 and the fifth sub-matrix structure 310 include parity check bits. The sixth sub-matrix structure 312 is an identity matrix.

In the first basic diagram structure of the LDPC code, the horizontal length 322 of the first submatrix 302 has a value of 22, and the vertical length 314 has a value of 4 or 5. The horizontal length 324 and the vertical length 314 of the second sub-matrix 304 both have a value of 4 or 5. The horizontal length 326 of the third sub-matrix 306 has a value of 42 or 41 and the vertical length 314 has a value of 4 or 5. The vertical length 316 of the fourth sub-matrix 308 has a value of 42 or 41 and the horizontal length 322 has a value of 22. The horizontal length 324 of the fifth sub-matrix 310 has a value of 4 or 5, and the vertical length 316 has a value of 42 or 41. The horizontal length 326 and the vertical length 316 of the sixth sub-matrix 312 have both values of 42 or 31.

In the second basic diagram structure of the LDPC code, the horizontal length 322 of the first submatrix 302 has a value of 10, and the vertical length 314 has a value of 7. The horizontal length 324 and the vertical length 314 of the second sub-matrix 304 have a value of 7. The horizontal length 326 of the third sub-matrix 306 has a value of 35 and the vertical length 314 has a value of 7. The vertical length 316 of the fourth sub-matrix 308 has a value of 35 and the horizontal length 322 has a value of 10. The horizontal length 324 of the fifth sub-matrix 310 has a value of 7 and the vertical length 316 has a value of 35. The horizontal length 326 and the vertical length 316 of the sixth sub-matrix 312 have a value of 35.

In the first basic diagram structure of the LDPC code, one supportable code block size is 22 khz (Z ═ a × 2j, and Z is as shown in [ table 3] below, the maximum size of one supportable code block is 8448, and the minimum size of one supportable code block is 44.

[ Table 3]

In the first basic diagram structure of the LDPC code, the size of one supportable code block is as follows.

44，66，88，110，132，154，176，198，220，242，264，286，308，330，352，296，440，484，528，572，616，660，704，792，880，968，1056，1144，1232，1320，1408，1584，1760，1936，2112，2288，2464，2640，2816，3168，3520，3872，4224，4576，4928，5280，5632，6336，7040，7744，8448，(5984，6688，7392，8096)

In the above sizes, may be additionally included (5984, 6688, 7392, 8096).

Based on the first basic graph (BG #1) of the LDPC code, a total of M maximum exponential matrices are additionally defined

In general, M may have a value of 8 or a random natural value, and i has a value of 1 to M. Terminal usage matrix

Downlink data decoding or uplink data encoding is performed. Matrix array

Has a specific element value shifted from a first basic graph (BG #1) of the LDPC code. I.e. a matrix

May have different shift values.

In the first basic diagram structure of the LDPC code, one supportable code block size is 10 khz (Z ═ ax2j, and Z is shown in table 4 below, the maximum size of one supportable code block is 2560 (or 3840), and the minimum size of one supportable code block is 20.

[ Table 4]

In the second basic diagram structure of the LDPC code, the size of one supportable code block is as follows. 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 180, 200, 220, 240, 260, 280, 300, 320, 360, 400, 440, 480, 520, 560, 600, 640, 720, 800, 880, 960, 1040, 1120, 1200, 1280, 1440, 1600, 1760, 1920, 2080, 2240, 2400, 2560(2880, 3200, 3520, 3840, 2720, 3040, 3360, 3680)

Among the above sizes, (2880, 3200, 3520, 3840, 2720, 3040, 3360, 3680) are values that may be additionally included.

Based on the second basic graph (BG #2) of the LDPC code, a total of M maximum exponential matrices are additionally defined

In general, M may have a value of 8 or a random natural value, and i may have a value of 1 to M. Terminal usage matrix

Downlink data decoding or uplink data encoding is performed. Matrix array

Has a specific element value shifted from the second basic graph (BG #2) of the LDPC code. I.e. a matrix

May have different shift values.

As described above, two types of basic diagrams are provided in the next generation mobile communication system. Therefore, a specific terminal may support only the first basic diagram or the second basic diagram, or there may be a terminal supporting both basic diagrams. They are listed in table 5 shown below.

[ Table 5]

When receiving downlink data information from a base station through downlink control information, a base map in which a terminal supporting type 1 determines a type to apply to a transport block including the downlink data information is always a first base map, and a maximum exponential matrix is applied

Applied to data encoding or decoding. When receiving downlink data information from a base station through downlink control information, a terminal supporting type 2 determines that a basic map applied to a transport block including the downlink data information is always a second basic map, and maps a maximum exponential matrix

Applied to data encoding or decoding. When receiving downlink data information from a base station through downlink control information, a terminal supporting type 3 previously transmits the downlink control information through higher layer signaling such as SIB, RRC, or MAC CE or through downlink control information transmitted in a UE group common control channel, a UE (cell) common control channel, or a UE-specific control channel,a configuration of a basic map applied to a transport block including downlink data information is received from a base station. The downlink control information may be included together with the transport block scheduling information or separately.

Fig. 4 is a block diagram illustrating a reception process of a terminal according to an embodiment of the present disclosure.

In fig. 4, in step 400, the terminal receives downlink control information through a UE (cell) common downlink control channel, a UE group common downlink control channel, or a UE-specific downlink control channel.

In step 410, the terminal determines whether the received downlink control information corresponds to one of the following conditions, or a combination of two or more.

A. RNTI scrambled in CRC of Downlink control information

B. Size of transport block included in downlink control information

C. Basic picture indicator included in downlink control information

D. Scheduling related values included in downlink control information

If the RNTI scrambled in the CRC of the downlink control information as condition a is an RNTI (e.g., semi-persistent scheduling (SPS) -RNTI or cell RNTI (C-RNTI)) other than Random Access (RA) -RNTI, paging-RNTI (P-RNTI), System Information (SI) -RNTI, Single Cell (SC) -RNTI, or group-RNTI (G-RNTI), the terminal determines condition 1 and performs operation 1 in step 420.

If the RNTI scrambled in the CRC as the downlink control information of condition A is RA-RNTI, P-RNTI, SI-RNTI, SC-RNTI, or G-RNTI, the terminal determines condition 2 and performs operation 2 in step 430.

If the size of a transport block included in the downlink control information as condition B and the CRC is greater than or equal to a predetermined threshold (Delta)₁) The terminal determines condition 1 and performs operation 1 in step 420.

If the size of a transport block included in the downlink control information as condition B and the CRC is equal to or less than a predetermined threshold (Delta)₂) Then, in step 430, the terminal determinesCondition 2 and perform operation 2.

Threshold value (Delta)₁) Or threshold value (Δ)₂) May be a value fixed to 2560 (or 3840, 960, 1040, 1120, 170, 640 or a predetermined value). Further, the threshold value (Δ)₁) Or threshold value (Δ)₂) May be the same as or different from each other.

Alternatively, the threshold value (Δ)₁) Or threshold value (Δ)₂) May be a value pre-configured through higher layer signaling such as SIB, RRC, or MAC CE, or a value configured through a UE group common downlink control channel, a UE common downlink control channel, or a UE specific downlink control channel. At this time, a value fixed to 2560 (or 3840, 960, 1040, 1120, 170, 640 or a predetermined value) may be used as the default threshold value (Δ) before the threshold value (Δ) is configured. Configuring a threshold value (Δ)₁) Or threshold value (Δ)₂) The previous time point refers to a time point before the terminal scrambles the CRC of the downlink control information using RA-RNTI, P-RNTI, SI-RNTI, SC-RNTI, or G-RNTI.

Alternatively, if the size of a transport block included in the downlink control information as the condition B and the CRC are smaller than 2560 (or 3840) (and larger than 160 or 640), and if K is satisfied>Code block length (K) of the first base map supportable code block length (K) and the second base map supportable code block length (K) of (transport block size + CRC size)_min) Belonging to the first basic diagram, the terminal determines condition 1 and performs operation 1 in step 420.

Alternatively, if the size of a transport block included in the downlink control information as the condition B and the CRC is less than 2560 (or 3840) (and greater than 160 or 640), and if the minimum code block length K among the code block lengths (K) supportable by the first base map and the code block length (K) supportable by the second base map satisfying K > (transport block size + CRC size) belongs to the second base map, the terminal determines the condition 2 and performs the operation 2 in step 430. .

This can be expressed using the following equation.

(TB+CRC)≤K≤V₂Where K ∈ K¹Or K ∈ K²

K*＝min(K)

If K ∈ K¹Condition 1 is satisfied, and thus operation 1 is performed in step 420

If K ∈ K²Condition 2 is satisfied, and thus operation 2 is performed in step 430

K is the code block length, K x is the selected code block length, and TB is the transport block size. Further, CRC is CRC size, K¹Is a set of code block lengths supportable by the first base picture, and K²Is a set of code block lengths supportable by the second base picture.

Alternatively, they may be expressed using the following equations.

V₁≤(TB+CRC)≤K≤V₂Where K ∈ K¹Or K ∈ K²

K*＝min(K)

K¹Is a first basic graph (or maximum exponential matrix)) A set of supportable code block lengths, and a type of the set may be one of the following values, or a combination of two or more. V₁May be 160, 640 or other values. V₂May be 2560, 3840, 960, 1040, 1120 or other values.

Alternatively, if TB + CRC is less than V in the above equation₁Then the maximum exponential matrix can be applied

One to perform decoding or encoding.If TB + CRC is greater than V in the above equation₂Then the maximum exponential matrix can be applied

One to perform decoding or encoding.

K¹Is a first basic graph (or maximum exponential matrix)

) A set of supportable code block lengths, and a type of the set may be one of the following values, or a combination of two or more. .

Cases where K is equal to or less than 2560

44，66，88，132，154，176，198，242，264，286，308，330，352，296，484，528，572，616，660，704，792，968，1056，1144，1232，1320，1408，1584，1936，2112，2288，2464

Case where K is 3840 or less

44，66，88，132，154，176，198，242，264，286，308，330，352，296，484，528，572，616，660，704，792，968，1056，1144，1232，1320，1408，1584，1936，2112，2288，2464，2640，2816，3168，3520

Case where K is equal to or less than 960

44，66，88，132，154，176，198，242，264，286，308，330，352，296，484，528，572，616，660，704，792

Case where K is equal to or less than 1040

44，66，88，132，154，176，198，242，264，286，308，330，352，296，484，528，572，616，660，704，792，968

Case where K is equal to or less than 1120

44，66，88，132，154，176，198，242，264，286，308，330，352，296，484，528，572，616，660，704，792，968，1056

If the values in the table are equal to or less than M, then they may generally be used while omitting all or some of the values from the table. 160. 640 or other values may be selected as M.

K²Is the second basic graph (or maximum exponential matrix)

) A set of supportable code block lengths, and a type of the set may be one of the following values, or a combination of two or more.

Cases where K is equal to or less than 2560

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960，1040，1120,1200，1280，1440，1600，1760，1920，2080，2240，2400，2560

Case where K is 3840 or less

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960，1040，1120,1200，1280，1440，1600，1760，1920，2080，2240，2400，2560，(2720，2880，3040，3200，3360，3520，3680，3840)

Case where K is equal to or less than 960

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960

Case where K is equal to or less than 1040

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960，1040

Case where K is equal to or less than 1120

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960，1040，1120

If the basic picture indicator included in the downlink control information as the condition C indicates 0 (or 1), the terminal determines the condition 1 and performs operation 1 in step 420.

If the basic picture indicator included in the downlink control information as the condition C indicates 1 (or 0), the terminal determines the condition 2 and performs the operation 2 in step 430.

If the MCS, RV, NDI, or frequency or time resource allocation value among the values related to scheduling included in the downlink control information as condition D indicates specific information, the terminal determines condition 1 and performs operation 1 in step 420.

If MCS, RV, NDI, or frequency or time resource allocation value among values related to scheduling included in the downlink control information as condition D indicates specific information, the terminal determines condition 2 and performs operation 2 in step 430.

If the terminal performs operation 1, the terminal performs one operation, or a combination of two or more operations.

1. The terminal is based on the first basic graph (or maximum exponential matrix)

) Supportable code block length, an attempt is made to decode a transport block indicated by the downlink control information.

2. The terminal attempts to decode a transport block indicated by the downlink control information based on the following table of supportable code blocks.

3. In a manner thatOne or more combinations of the code block sets available below correspond to terminal usage

Coded or decoded code blocks. For the corresponding code block, the terminal is based at least on the matrix supported by the first basic graph

Decoding of the transport block indicated by the downlink control information is attempted.

A.44，88，176，352，704，1408，2816，5632

B.44，66，110，154，198，242，286，330

C.44，66，154，198，242，286，330

4. In the code block set available below, one or more combinations thereof correspond to terminal usage

A.66，132，264，528，1056，2112，4224，8448

B.88，132，220，308，396，484，572，660

C.88，132，308，396，484，572，660

5. In the code block set available below, one or more combinations thereof correspond to terminal usage

Try to get the data from the downlinkAnd decoding the transmission block indicated by the path control information.

A.110，220，440，880，1760，3520，7040

B.176，264，440，616，792，968，1144，1320

C.1760，3520，7040

D.3520，7040

E.7040

F.176，264，616，792，968，1144，1320

6. In the code block set available below, one or more combinations thereof correspond to terminal usage

A.154，308，616，1232，2464，4928

B.352，528，880，1232，1584，1936，2288，2640

C.352，528，1232，1584，1936，2288，2640

7. In the code block set available below, one or more combinations thereof correspond to terminal usage

A.198，396，792，1584，3168，6336

B.704，1056，1760，2464，3168，3872，4576，5280

C.704，1056，2464，3168，3872，4576，5280

8. In the code block set available below, one or more combinations thereof correspond to terminal usage

Attempting to decode a transport block indicated by downlink control information

A.242，484，968，1936，3872

B.1408，2112，3520，4928，6336，7744

C.1408，2112，4928，6336，7744

9. In the code block set available below, one or more combinations thereof correspond to terminal usage

A.286，572，1144，2288，4576

B.2816，4224，7040

10. In the code block set available below, one or more combinations thereof correspond to terminal usage

A.330，660，1320，2640，5280

B.5632，8448

If the terminal performs operation 2, the terminal performs one of the following operations, or a combination of two or more of the following operations.

1. The terminal attempts to decode a transport block indicated by the downlink control information based on a code block length supportable by the second basic picture.

2. The terminal attempts to decode the transport block indicated by the downlink control information based on the following table of supportable code blocks.

20，30，40，50，60，70，80，90，100，110，120，130，140，150，160，180，200，220，240，260，280，300，320，360，400，440，480，520，560，600，640，720，800，880，960，1040，1120,1200，1280，1440，1600，1760，1920，2080，2240，2400，2560(2880，3200，3520，3840，2720，3040，3360，3680)

3. In the code block set available below, one or more combinations thereof correspond to terminal usage

Coded or decoded code blocks. For the corresponding code block, the terminal is based at least on the matrix supported by the second basic diagram

A.20，40，80，160，320，640，1280

B.20，30，50，70，90，110，130，150

A.30，60，120，240，480，960，1920，(3840)

B.40，60，100，140，180，220，260，300

A.50，100，200，400，800，1600，(3200)

B.80，120，200，280，360，440，520，600

A.70，140，280，560，1120，2240

B.160，240，400，560，720，880，1040，1200

A.90，180，360，720，1440，(2880)

B.320，480，800，1120，1440，1760，2080，2400

A.110，220，440，880，1760，(3520)

B.640，960，1600，2240，(2880)，(3520)

A.130，260，520，1040，2080

B.1280，1920，(3200)

Coded or decoded code blocks. For the corresponding code block, the terminal is based on at least the secondMatrix supported by basic diagram

A.150，300，600，1200，2400

B.2560，(3840)

In the present disclosure, numerals in parentheses indicate that the corresponding values may or may not be included.

In the present disclosure, the information bits may refer to an amount of data to be transmitted from a higher layer or a Transport Block Size (TBS). The TBS is typically transmitted during one TTI, but may be transmitted over multiple TTIs. In the present disclosure, TBS is indicated by N.

In the present disclosure, a value in parentheses shown in a table is a value that may be wholly or partially included in the table, or all or some of the values may not be partially included in the table.

Fig. 5 illustrates a method of segmenting one transport block into one or more Code Blocks (CBs). Referring to fig. 5, a CRC503 may be added to the last part or the first part of one transport block 501 to be transmitted in uplink or downlink. The CRC may have 16 bits, 24 bits, a predetermined number of bits, or a variable number of bits according to channel conditions, and may be used to determine whether channel coding is successful. The

blocks

501 and 503 to which the TB and the CRC are added may be segmented into a plurality of code blocks 507, 509, 511, and 513 as indicated by reference numeral 505.

The code blocks may be segmented after the maximum size of the code block is predetermined, in which case the last code block 513 may be smaller than the other code blocks or may have the same length as the other code blocks by inserting 0, a random value, or 1.

CRCs

517, 519, 521, and 523 may be respectively added to the segmented code blocks, as indicated by reference numeral 515. The CRC may have 16 bits, 24 bits, or a predetermined number of bits, and may be used to determine whether the channel coding is successful. However, the CRC503 added to the TB and the

CRCs

517, 519, 521, and 523 added to the segmented code blocks may have variable lengths depending on the type of channel code to be applied to the code blocks. Further, when a polarization code is used, a CRC may be added or omitted. In the splitting process, if the number of CBs is one, the CRC517 added to the CB may be omitted.

The CRC inserted into the TB for determining whether TB decoding is successful after the receiver performs TB decoding has a length of L, and L may have at least two available values. That is, if a transport block is segmented into two or more code blocks and transmitted, a long CRC may be used. On the other hand, if a transport block is segmented into one code block and transmitted, a short CRC may be used. If the LDPC code is used for encoding in a mobile communication system, the LDPC code itself has a parity check function, and thus may have a function of determining whether decoding is successful without inserting CRC.

If the LDPC code is used in a specific mobile communication system and it is desired to obtain an additional level of successful determination of decoding, a technique for determining whether decoding is finally successful may be used in addition to the parity check function of the inserted LDPC code, and thus a determined error rate level desired by the system as to whether decoding is successful may be obtained. For example, if the error rate required by the system for the determination of whether the decoding was successful is 10^-6And the determined error rate obtained by the parity check function of the LDPC code is 10^-3By additionally inserting a 10^-3May be implemented 10^-6The final system of (1) determines the error rate.

In general, as the length of the CRC is longer, the error rate of the determination as to whether the decoding is successful becomes lower. If a transport block is divided into two or more code blocks and transmitted, the TB itself is configured by concatenation of LDPC codes, and thus the parity check function of the LDPC codes cannot be used. On the other hand, if the transport block includes one code block, the parity check function of the LDPC code may be used. Thus, in a particular system, the TB may be used after a long CRC or a short CRC is inserted into the TB according to the number of code blocks within the transport block. In the embodiments of the present disclosure, it is assumed that a long length L + or a short length L-may be used as the length L of the CRC inserted into the TB, depending on whether the TB is segmented into two or more code blocks. The value available for L + may be 24, which is used in the LTE system, and any length shorter than 24 may be used for L-, and 16, which is used by the control channel of the LTE system, may be reused. However, in embodiments of the present disclosure, L-is not limited to 16.

Whether a specific TB is segmented into a plurality of code blocks is determined according to whether a given TB can be transmitted using one code block, and thus the determination may be performed as follows:

-if N + L-is equal to or less than the maximum available CB length, transmitting the TB using one code block (if (N + L-)<＝K_maxThen use a CB)

-if N + L-is larger than the maximum available CB length, segmenting TB into multiple code blocks and transmitting (if (N + L-)>K_maxThen, the CB is divided

K_maxIndicating the largest code block size among the available code block sizes.

In the conventional LTE system, the MCS index transmitted through DCI and the number of allocated PRBs are used to determine the TBS. Based on the downlink, a 5-bit MCS index may be transmitted, and thus may be selected from table 6 below]Deriving modulation order Q_mAnd a TBS index.

[ Table 6]

The number of PRBs used for data transmission may be derived from resource allocation information transmitted through DCI, and the TBS may be determined based on the TBS index derived from table 7 below and table 6 above.

[ Table 7]

Table 7 above is a TBS table in the case where PRBs are 1 to 10 and TBS indexes are 0 to 26, or even used in the case where PRBs are maximum 110 and an additional TBS index is used. The number in space corresponding to the number of allocated PRBs and the TBS index in the above table is the TBS understood by the base station and the terminal.

The methods and apparatuses for determining a TBS for downlink data transmission by a terminal described in the present disclosure may be fully applied to a process of encoding a transport block of an uplink data channel. In addition, the encoding and decoding operations of the terminal described in the present disclosure may be sufficiently applied to the encoding and decoding operations of the base station.

In the present disclosure, a transport block may be data transmitted from a higher layer to a physical layer, and may be a unit that may be initially transmitted by the physical layer.

In the present disclosure, N1_ max and N2_ max may indicate a maximum code block length when BG #1 is used in the LDPC code and a maximum code block length when BG #2 is used. For example, N1_ max is 8448 and N2_ max is 3840. However, embodiments of the present disclosure are not limited thereto. In the present disclosure, N1_ max may be compared to N_1maxOr N_1,maxUsed interchangeably, and N2_ max can be used with N_2maxOr N_2,maxAre used interchangeably.

In the present disclosure, L _ { TB, 16} and L _ { TB, 24} may be lengths of CRCs added to TBs, and L _ { TB, 16} < L _ { TB, 24 }. For example, L _ { TB, 16} may be 16, and L _ { TB, 24} may be 24. In this disclosure, L _ { TB, 16} can be compared with L_TB,16Used interchangeably, and L _ { TB, 24} can be substituted with L_TB,24Are used interchangeably. In the present disclosure, L _ { CB } may be the length of CRC added to the CB, and may be identical to L_CBAre used interchangeably.

[ example 1]

Example 1 provides a method to determine TBS based on CB-CRC and Basic Graph (BG) selection. The present embodiment can be applied to the following cases: in a specific case, when the TBS is large, the TB is divided into two or more code blocks, and each code block is channel-encoded into an LDPC code using BG # 2. That is, even when the TBS is large, the present embodimentIt is also applicable to a case where data can be transmitted using BG # 2. In the present embodiment, R _1 and R _2 may indicate a code rate as a reference for selecting BG #1 or BG #2, and may be identical to R₁And R₂Are used interchangeably. For example, R ₁1/4 and R ₂2/3, the methods provided by the present disclosure are not so limited. Further, R, R indicated as a code rate may be represented and determined in various ways such as fractional and fractional in this disclosure₁And R₂. For example, R may be a value such as 0.28, but is not limited thereto, and various digital sum values may be used. When selecting BG between BG #1 and BG #2 in data transmission, a code rate and a soft buffer of a terminal may be considered.

The base station may transmit data by allocating frequency resources of a predetermined number of PRBs and time resources of a predetermined number of slots or symbols to the terminal, and may transmit scheduling information related thereto to the terminal through Downlink Control Information (DCI), a configuration transmitted through higher layer signaling, or a combination thereof. If scheduling information of the base station and the terminal is given, the TBS may be determined in the following order.

-step 1-1: determining the number of temporary information bits (A)

-step 1-2: procedures for determining the number of temporary CBs (C), performing byte alignment (making A a multiple of 8), and making A a multiple of the number of CBs (B multiple)

-step 1-3: procedure for determining the number of CRC bits (TBS) in addition to the TBS

In step 1-1, a temporary TBS value is determined considering the amount of resource regions to which data to be transmitted can be mapped. Can pass code rate (R), modulation order (Q)_m) Number of REs (N) to which rate matching data is mapped_RE) The number of temporary information bits is determined by a combination of one or more of reference values of the number of allocated PRBs or RBs (# PRBs), the number of allocated OFDM symbols, the number of allocated slots, and the number of mapped REs within one PRB. For example, the following [ equation 10] may be used]To determine a.

[ equation 10]

A＝N_RE×Q_m×R×v

Modulation order Q_mAnd the code rate R may be transmitted to the terminal while being included in the DCI. The number of layers v used for transmission may be sent to the terminal via DCI, higher layer signaling, or a combination thereof. N is a radical of_REThe number of REs to which data is mapped through rate matching when transmitting data may be used by the base station to determine, and if the base station and the terminal both know resource allocation information, the base station and the terminal may equally understand N_RE. When calculating N_REWhen data is mapped in a rate matching scheme, REs to which the data is not actually mapped are included in N due to the data being punctured for a particular reason, such as transmission of a channel state information reference signal (CSI-RS), URLLC, or Uplink Control Information (UCI)_REIn (1). This is in order for both the base station and the terminal to understand the TBS equally even when the base station does not transmit some data scheduled to be mapped in the puncturing scheme without notifying the terminal.

Can define a table such as the following [ Table 8]]And the base station may transmit the MCS index to the terminal to transmit the Q-related_mAnd information of R. The modulation order refers to information such as QPSK, 16QAM, 64QAM, 256QAM, or 1024 QAM. In the case of QPSK, Q _m2, in the case of 16QAM, Q_m4, in case of 64QAM, Q_m6, in case of 256QAM, Q_m8 and in the case of 1024QAM, Q_m10. Namely, Q_mMay be the number of bits that may be transmitted in a modulation symbol.

[ Table 8]

Above [ Table 8]In, Q_mIs transmitted together with R through a 5-bit MCS index, but may be transmitted to a terminal in various methods such that Q is transmitted_mAnd R is through DCI is sent with a 6-bit MCS index, or so that Q is 3-bit_mAnd 3 bits of R each use a bit field. Alternatively, a ═ (number of allocated PRBs) × (number of reference REs per PRB) × Q_m×R×v。

Step 1-2 is a step of determining the number C of temporary code blocks (the number of temporary CBs) using the determined a, and making a multiple of 8 and a multiple of the number of temporary CBs based thereon. This is to align the finally determined TBS and the length of the CRC added to the TB in bytes, and is also a multiple of CB. First, the number of temporary CBs can be determined by the following [ pseudo code 1 ].

[ pseudo code 1]

[Start]

If R≤R₁,then

Else

End if of R

[End]

R is a code rate, and may be a value transmitted through DCI as described above. As mentioned above, R₁May be 1/4, N_1,maxMay be 8448, and N_2,maxMay be 3840. In this case, pseudo code 2 may be used]The determination is made, but is not limited thereto. At this time, R is given by way of example₁、N_1,maxAnd N_2,maxDescribed as 1/4, 8448, and 3840, but is not limited thereto, and other values may be used.

[ pseudo code 2]

[Start]

If R≤1/4,then

Else

End if of R

[End]

The above obtained C may be the number of temporary CBs. CB splitting is performed when the TB is finally transmitted, and the number of temporary CBs may be different from the number of obtained actual CBs. It may be determined that the numbers of the actual CBs and the temporary CBs may be identical to each other.

Then, a process of generating B by making a determined in step 1-1 a multiple of 8 and C is performed to prevent unnecessary bits or unnecessary zero-padded bits from being included in all code blocks. B can be calculated as shown in Table 11 below.

[ equation 11]

Above [ equation 11]Can be changed into

B ═ a + (8C-mod (a, 8C)), and B ═ a-mod (a, 8C), then applied. In this disclosure, mod (x, y) may be a remainder obtained by dividing x by y, and may be transformed into

And then applied. In the context of the present disclosure, it is,

is the smallest integer greater than x and may be used interchangeably with ceil (x).

Is the largest integer less than x and may be used interchangeably with floor (x). [ equation 11)]Can be changed into

Which means that B is a multiple of the nearest 8C to a. Round (x) may be the nearest integer to x, or x rounded off.

[ equation 11)]Will makeA is a multiple of 8C, but can be transformed into an equation such that a is a common multiple or a least common multiple of 8 and C, and then applied. Thus, above [ equation 11]Can be transformed into

Or

And then applied. LCM (a, b) is the least common multiple of a and b.

The information bits transmitted in the allocated resources are obtained in steps up to step 1-2, and a process of excluding the number of bits added for the CRC from the obtained information bits to be transmitted is performed in the last step 1-3. This can be performed by the following [ pseudo-code 3 ].

[ pseudo code 3]

If each parameter value is determined and applied as described above, the [ pseudo code 3] may be applied to the following [ pseudo code 4], but is not limited thereto.

[ pseudo code 4]

Since the CRC length applied to the TB varies according to the TBS, L_TB,16And L_TB,24Are considered. The CRC added to the CB may be omitted if the number of code blocks is 1, or the CRC length added to the CB may be 0.

In another example, steps 1-3 may be transformed to [ pseudocode 5] or [ pseudocode 6] below and then applied.

[ pseudo code 5]

[Start]

If B≤N_2,max,then TBS＝B-L_TB,16

Else TBS＝B-L_TB,24

End if of B

[End]

[ pseudo code 6]

[Start]

If B≤3840,then TBS＝B-16

Else TBS＝B-24

End if of B

[End]

In [ pseudocode 5] or [ pseudocode 6], the CRC length added to the CB is not excluded to obtain the final TBS. Therefore, when actual data is subsequently mapped and transmitted, the CRC length of the CB may be added to the obtained TBS, so that the actual code rate may be greater than R.

Fig. 6 is a flowchart illustrating steps in which a base station and a terminal obtain a TBS and transmit and receive data when scheduling and transmitting downlink or uplink data. When the scheduling and data transmission procedure starts, the base station determines scheduling information in step 602 and transmits the scheduling information to the terminal through a combination of one or more of DCI, system information, mac ce, and RRC signaling in step 604. The terminal and the base station obtain the TBS from the determined scheduling information in step 606. In step 606, the TBS may be obtained using step 1-1, step 1-2, and step 1-3 described above. Step 1-1, step 1-2 and step 1-3 may be combined and performed simultaneously, or the order thereof may be changed. Thereafter, in step 608, CB partitioning and channel coding, decoding and retransmission operations are performed using the TBS, which completes data scheduling and transmission.

The TBS determination method provided by the embodiments can only be applied to the following cases: a specific combination of MCS index and the number of allocated PRBs prearranged between the base station and the terminal is not applied. For example, if the scheduling is determined using MCS index 6 and the number of PRBs is 1, the TBS may be determined as a fixed value 328 and data may be transmitted instead of using the above-described method. Therefore, the base station and the terminal may determine and know the TBS value in advance according to a combination of { MCS index or code rate index, number of PRBs }, and may determine the TBS by the method provided by the embodiment only in cases other than the combination.

The TBS determination method according to the present embodiment corresponds to only initial transmission, and in retransmission, transmission and reception may be performed on the assumption that the TBS determined in the initial transmission corresponds to retransmission.

[ example 2]

[ example 2]A method is provided for determining TBS based on CB-CRC and BG selections. The present embodiment can be applied to the following cases: in a specific case, when the TBS is large, the TB is divided into two or more code blocks, and each code block is channel-encoded into an LDPC code using BG # 2. That is, even when the TBS is large, the present embodiment can be applied to a case where data can be transmitted using BG # 2. In the present embodiment, R _1 and R _2 may indicate a code rate as a reference for selecting BG #1 or BG #2 of LDPC, and R₁And R₂May be used interchangeably. For example, R ₁1/4 and R ₂2/3, the methods provided by the present disclosure are not so limited. Further, in this disclosure R, R referring to code rate may be represented and determined in various ways, e.g., as fractions and fractions₁And R₂. When selecting BG between BG #1 and BG #2 in data transmission, a code rate and a soft buffer of a terminal may be considered. In this embodiment, the process of making TBS a multiple of 8, a multiple of the number of CBs, or a common multiple or the least common multiple of 8 and the number of CBs may be performed at the end of the TBS calculation.

The base station may transmit data by allocating frequency resources of a predetermined number of PRBs and time resources of a predetermined number of slots or symbols to the terminal, and may transmit scheduling information related thereto to the terminal through Downlink Control Information (DCI), a configuration transmitted through higher layer signaling, or a combination thereof. When scheduling information of a base station and a terminal is given, TBS may be determined in the following order.

-step 2-1: determining the number of temporary information bits (A)

-step 2-2: determining the number of temporary CBs (C) using the determined A, determining the TBS by making the values obtained by adding the TB-CRC length to the TBS byte-aligned (multiple of 8) and controlling A to be multiple of the number of temporary CBs

Step 2-1 may be performed in combination with [ example 1]]The procedure in step 1-1 is the same. In [ step 2-1 ]]The temporary TBS value is determined in consideration of an amount of a resource region to which data to be transmitted can be mapped. Can pass code rate (R), modulation order (Q)_m) Number of REs (N) to which rate matching data is mapped_RE) The number of temporary information bits is determined by a combination of one or more of reference values of the number of allocated PRBs or RBs (# PRBs), the number of allocated OFDM symbols, the number of allocated slots, and the number of mapped REs within one PRB.

For example, A may be represented by equation 10, corresponding to above]A ═ N_RE×Q_mXrxv. Modulation order Q_mAnd the code rate R may be transmitted to the terminal while being included in the DCI. The number of layers v used for transmission may be sent to the terminal via DCI, higher layer signaling, or a combination thereof. N is a radical of_REThe number of REs to which data is mapped through rate matching when transmitting data may be used by the base station to determine, and if the base station and the terminal both know resource allocation information, the base station and the terminal may equally understand N_RE. When calculating N_REIn time, data is mapped by rate matching, but REs to which the data is not mapped due to data puncturing for a specific reason (such as CSI-RS, URLLC, or UCI transmission) are included in N_REIn (1). This is in order for both the base station and the terminal to understand the TBS equally even when the base station does not transmit some data scheduled to be mapped in the puncturing scheme without notifying the terminal.

Can define a table such as above]And the base station may transmit the MCS index to the terminal to transmit the Q-related_mAnd information of R. The modulation order refers to information such as QPSK, 16QAM, 64QAM, 256QAM, or 1024 QAM. In the case of QPSK, Q _m2, in the case of 16QAM, Q_m4, in case of 64QAM, Q_m6, in case of 256QAM, Q_m8 and in the case of 1024QAM, Q_m10. Namely, Q_mMay be the number of bits that may be transmitted in a modulation symbol. Above [ Table 8]In, Q_mAnd R are transmitted together with the MCS index of 5 bits, but may be transmitted to the terminal in various methods,so that Q_mAnd R is transmitted through DCI by a 6-bit MCS index, or so that Q is 3 bits_mAnd 3 bits of R each use a bit field. Alternatively, a ═ (number of allocated PRBs) × (number of reference REs per PRB) × Q_m×R×v。

Step 2-2 may be performed as shown in [ pseudocode 7] or [ pseudocode 8] below.

[ pseudo code 7]

Can be transformed into

And then applied.

[ pseudo code 8]

The above [ pseudo-code 7] can be converted into the following [ pseudo-code 7-A ], [ pseudo-code 7-B ], or [ pseudo-code 7-C ], and then applied. The following pseudo code segment may be a method based on the assumption that the TB-CRC has been added.

[ pseudo code 7-A ]

[ pseudo code 7-B ]

I_MCSMay be an MCS index or a parameter or code rate related to the MSC. I is_MCS,BG#2May be I for selecting BG #2_MCSTo the reference value of (c).

[ pseudo code 7-C ]

α is a quantization factor and may be a value used to determine the granularity of the TBS a may be a value set by the base station and the terminal and thus known by the base station and the terminal, or may be a value configured in the terminal by the base station through higher layer signaling α may alternatively be a value determined from the value of a or C.

The above [ pseudo-code 8] can be transformed into the following [ pseudo-code 8-a ] and then applied.

[ pseudo code 8-A ]

"If R ≦ 1/4," not limited to "1/4" and may be transformed to a value of, for example, "If R ≦ 0.28," and then applied. Such conditional statements may be in the form of comparison MCS indices, such as "If I_MCS≦ 3, ", and is applied.

In the above pseudo code segment, L_TB,16And L_TB,24May be different values. The number of CRC bits applied to the value divided by a when calculating C and the value excluding the CRC bits from the process of calculating TBS may vary according to the code rate R and the size of a calculated.

Can be transformed into

A + (8-mod (A,8)), A-mod (A,8), or

Then as in [ example 1]]The application is described. In addition, the first and second substrates are,

can be converted into a- (C × 8-mod (a +24, C × 8)) or a-mod (a +24, C × 8) and then applied. In addition to this, the present invention is,

can be transformed into

And then applied. Thus, the pseudo code can be converted into the following pseudo code 9]And then applied. In addition, the application may be executed using another equation that yields the same result.

[ pseudo code 9]

Step 2-2 may be a process of determining the number of temporary code blocks C (the number of temporary CBs) using the determined a, and based thereon making the length of CRC + TB of the TBS a multiple of 8 and C.

In this disclosure, mod (x, y) may be a remainder obtained by dividing x by y, and may be transformed into

In the context of the present disclosure, it is,

Is the largest integer less than x and may be used interchangeably with floor (x). Round (x) may be the nearest integer to x, or x rounded off.

In the equation provided in the present embodiment, C × 8 is used for the multiple of the product of 8 and C, but C × 8 may be converted into LCM (8, C) and applied to the above equation.

Fig. 6 is a flowchart illustrating steps in which a base station and a terminal obtain a TBS and transmit and receive data when scheduling and transmitting downlink or uplink data. If the scheduling and data transmission procedure starts, the base station determines scheduling information in step 602 and transmits the scheduling information to the terminal through a combination of one or more of DCI, system information, mac ce, and RRC signaling in step 604. The terminal and the base station obtain the TBS from the determined scheduling information in step 606. In step 606, the TBS may be calculated using step 2-1 and step 2-2, described above. Step 2-1 and step 2-2 may be combined and performed simultaneously, or the order thereof may be changed. Thereafter, in step 608, CB partitioning and channel coding, decoding and retransmission operations are performed using the TBS, which completes data scheduling and transmission.

The TBS determination method provided by the embodiments can only be applied to the following cases: a specific combination of MCS index and the number of allocated PRBs prearranged between the base station and the terminal is not applied. For example, if the scheduling is determined using MCS index 6 and the number of PRBs is 1, the TBS may be determined as a fixed value 328 and data may be transmitted, instead of through the above-described method. Therefore, the base station and the terminal may determine and know the TBS value in advance according to a combination of { MCS index or code rate index, number of PRBs }, and may determine the TBS by the method provided by the embodiment only in cases other than the combination.

The TBS determination method according to the present embodiment may correspond to only initial transmission, and in retransmission, transmission and reception may be performed on the assumption that the TBS determined in the initial transmission corresponds to retransmission.

Steps 2-1 and 2-2 may correspond to steps 2-A, 2-B, 2-C, and 2-D below.

Step 2-a: determining the number of resources on which data resources are rate matched (step 2-A: for PDSCH/PUSCH (N)_RE) Count the number of available REs for rate matching)

Step 2-B: n calculated by multiplying the coding rate, the number of layers and the modulation order by_REA temporary TBs including a TB-CRC is calculated (step 2-B: by multiplying the coding rate, modulation order and number of layers by N_RETo calculate TBS + TB-CRC)

Step 2-C: the calculated temporary TBS including TB-CRC is made to be a common multiple of the number of 8 and CB, or a multiple of a value obtained by multiplying the number of 8 and CB (step 2-C: TBS + TB-CRC is made to be a common multiple of the number of 8 and CB)

Step 2-D: the final TBS is calculated in consideration of a specific packet size or a specific service. In case there is no specific packet size or specific service, a final TBs excluding the TB-CRC length from the values calculated in step 2-C is calculated (step 2-D: the final TBs is determined taking into account the specific number of packet sizes and services, if applicable).

[ example 3]

[ example 3]A method for TBS determination based on the selection of CB-CRC and BG is provided. The present embodiment can be applied to the following specific cases: when TBS is large, BG #2 is not applied. That is, in the present disclosure, the case of channel-coding a code block into an LDPC code using BG #2 can be limitedly applied only to the case of not dividing the TB into a plurality of code blocks. In the present embodiment, R _1 and R _2 may indicate a code rate as a reference for selecting BG #1 or BG #2 of LDPC, and R₁And R₂May be used interchangeably. For example, R ₁1/4 and R ₂2/3, the methods provided by the present disclosure are not so limited. Further, in this disclosure R, R referring to code rate may be represented and determined in various ways, e.g., as fractions and fractions₁And R₂. When selecting BG between BG #1 and BG #2 in data transmission, the code rate and the bit rate of the terminal may be consideredA soft buffer.

-step 3-1: determining the number of temporary information bits (A)

-step 3-2: procedures for determining the number of temporary CBs (C), performing byte alignment (making A a multiple of 8), and making A a multiple of the number of temporary CBs (B multiple)

-step 3-3: a process of determining the TBS except for the number of CRC bits.

Step 3-1 may be performed in combination with [ example 1]]The procedure in step 1-1 is the same. In [ step 3-1 ]]The temporary TBS value is determined in consideration of an amount of a resource region to which data to be transmitted can be mapped. Can pass code rate (R), modulation order (Q)_m) Number of REs (N) to which rate matching data is mapped_RE) The number of temporary information bits is determined by a combination of one or more of reference values of the number of allocated PRBs or RBs (# PRBs), the number of allocated OFDM symbols, the number of allocated slots, and the number of mapped REs within one PRB.

For example, A may be represented by a code corresponding to [ equation 10]]A ═ N_RE×Q_mXrxv. Modulation order Q_mAnd the code rate R may be transmitted to the terminal while being included in the DCI. The number of layers v used for transmission may be sent to the terminal via DCI, higher layer signaling, or a combination thereof. N is a radical of_REThe number of REs to which data is mapped through rate matching when transmitting data may be used by the base station to determine, and if the base station and the terminal both know resource allocation information, the base station and the terminal may equally understand N_RE. When calculating N_REIn time, data is mapped by rate matching, but REs to which the data is not mapped due to data puncturing for a specific reason (such as CSI-RS, URLLC, or UCI transmission) are included in N_REIn (1). This is in order for both the base station and the terminal to understand the TBS equally even when the base station does not transmit some data scheduled to be mapped in the puncturing scheme without notifying the terminal.

Can define a table such as above]And the base station may transmit the MCS index to the terminal to transmit the Q-related_mAnd information of R. The modulation order refers to information such as QPSK, 16QAM, 64QAM, 256QAM, or 1024 QAM. Above [ Table 8]In, Q_mIs transmitted together with R through a 5-bit MCS index, but may be transmitted to a terminal in various methods such that Q is transmitted_mAnd R is transmitted through DCI by a 6-bit MCS index, or so that Q is 3 bits_mAnd 3 bits of R each use a bit field. Alternatively, a ═ (number of allocated PRBs) × (number of reference REs per PRB) × Q_m×R×v。

Step 3-2 is a step of determining the number C of temporary code blocks (the number of temporary CBs) using the determined a, and making a multiple (B multiple) of 8 and the number of temporary CBs. This is to align the finally determined TBS and the length of the CRC added to the TB in bytes, and is also a multiple of CB.

First, the number of temporary CBs may be determined as

N_1,maxMay be 8448. The above obtained C may be the number of temporary CBs. CB splitting is performed when the TB is finally transmitted, and the number of temporary CBs may be different from the obtained number of actual CBs, but it may be determined that the numbers of actual CBs and temporary CBs may be identical to each other.

A process of generating B by making a determined in step 3-1 a multiple of 8 and C is performed, which is for preventing all code blocks from being transmitted while including unnecessary bits or unnecessary zero-padded bits. B can be as in [ equation 11]]

Is calculated as shown in (a). Above [ equation 11]Can be changed into

In the context of the present disclosure, it is,

Is the largest integer less than x and may be used interchangeably with floor (x).

[ equation 11)]Can be transformed into

And applied, this means that B is a multiple of 8C closest to a. Round (x) may be the nearest integer to x or x rounded off. [ equation 11)]For a to be a multiple of 8C, but may be transformed into an equation for a to be a common multiple or a least common multiple of 8 and C. Thus, above [ equation 11]Can be transformed into

Or

And then applied. LCM (a, b) is the least common multiple of a and b.

The information bits transmitted in the allocated resources are obtained in steps up to step 3-2, and a process of excluding the number of bits added for the CRC from the obtained information bits to be transmitted is performed in the last step 3-3. This can be determined by the following [ pseudocode 10] or [ pseudocode 11 ].

[ pseudo code 10]

[Start]

If B≤N_2,max,then TBS＝B-L_TB,16

Else if B≤N_1,max,then TBS＝B-L_TB,24

Else TBS＝B-L_TB,24-C×L_CB

End if of B

[End]

[ pseudo code 11]

[Start]

If B≤3840,then TBS＝B-16

Else if B≤8448,then TBS＝B-24

Else TBS＝B-24×(C+1)

End if of B

[End]

Since the CRC length applied to the TB varies according to the TBS, L is considered_TB,16And L_TB,24Are considered. The CRC added to the CB may be omitted if the number of code blocks is 1, or the CRC length added to the CB may be 0.

In another example, step 3-3 may be transformed to [ pseudocode 5] or [ pseudocode 6], and then applied. In [ pseudocode 5] or [ pseudocode 6], the CRC length added to the CB is not excluded in order to obtain the final TBS. Accordingly, when actual data is subsequently mapped and transmitted, a CRC length of CB may be added to the obtained TBS, and thus an actual code rate may be greater than R.

Fig. 6 is a flowchart illustrating steps in which a base station and a terminal obtain a TBS and transmit and receive data when scheduling and transmitting downlink or uplink data. When the scheduling and data transmission procedure starts, the base station determines scheduling information in step 602 and transmits the scheduling information to the terminal through a combination of one or more of DCI, system information, mac ce, and RRC signaling in step 604. The terminal and the base station obtain the TBS from the determined scheduling information in step 606. In step 606, the TBS may be obtained using step 3-1, step 3-2, and step 3-3 described above. Step 3-1, step 3-2 and step 3-3 may be combined and performed simultaneously, or the order thereof may be changed. Thereafter, in step 608, CB partitioning and channel coding, decoding and retransmission operations are performed using the TBS, which completes data scheduling and transmission.

[ example 4]

[ example 4]]A method for TBS determination based on the selection of CB-CRC and BG is provided. The present embodiment can be applied to the following specific cases: when TBS is large, BG #2 is not applied. That is, in the present disclosure, the case of channel-coding a code block into an LDPC code using BG #2 can be limitedly applied only to the case of not dividing the TB into a plurality of code blocks. In the present embodiment, R _1 and R _2 may indicate a code rate as a reference for selecting BG #1 or BG #2 of LDPC, and R₁And R₂May be used interchangeably. For example, R ₁1/4 and R ₂2/3, the methods provided by the present disclosure are not so limited. Further, in this disclosure R, R referring to code rate may be represented and determined in various ways, e.g., as fractions and fractions₁And R₂. When selecting BG between BG #1 and BG #2 in data transmission, a code rate and a soft buffer of a terminal may be considered. In this embodiment, the process of making TBS a multiple of 8, a multiple of the number of CBs, or a common multiple or the least common multiple of 8 and the number of CBs may be performed at the end of the TBS calculation.

-step 4-1: determining the number of temporary information bits (A)

-step 4-2: procedure for determining the number of temporary CBs such that values obtained by adding TB-CRC length to TBS are byte-aligned and are multiples of the number of CBs

Step 4-1 may be performed in combination with [ example 2]]The procedure in step 2-1 is the same. In [ step 4-1 ]]The temporary TBS value is determined in consideration of the number of resource regions to which data to be transmitted can be mapped. Can pass code rate (R), modulation order (Q)_m) Number of REs (N) to which rate matching data is mapped_RE) The number of temporary information bits is determined by a combination of one or more of reference values of the number of allocated PRBs or RBs (# PRBs), the number of allocated OFDM symbols, the number of allocated slots, and the number of mapped REs within one PRB. For example, this may be accomplished by [ equation 10] above]A is determined. Modulation order Q_mAnd the code rate R may be transmitted to the terminal while being included in the DCI. The number of layers v used for transmission may be sent to the terminal via DCI, higher layer signaling, or a combination thereof. N is a radical of_REThe number of REs to which data is mapped through rate matching when transmitting data may be used by the base station to determine, and if the base station and the terminal both know resource allocation information, the base station and the terminal may equally understand N_RE. When calculating N_REIn time, data is mapped by rate matching, but REs to which the data is not mapped due to data puncturing for a specific reason (such as CSI-RS, URLLC, or UCI transmission) are included in N_REIn (1). This is in order for both the base station and the terminal to understand the TBS equally even when the base station does not transmit some data scheduled to be mapped in the puncturing scheme without notifying the terminal.

Step 4-2 may be performed as shown in [ pseudocode 12] or [ pseudocode 13 ].

[ pseudo code 12]

[Start]

If A≤N_1,max-L_TB,24,

Else

End if of A

[End]

Can be transformed into

And then applied.

[ pseudo code 13]

Alternatively, [ pseudocode 12] can be transformed to [ pseudocode 14] and then applied.

[ pseudo code 14]

[Start]

[End]

Can be transformed into

A + (8-mod (A,8)), A-mod (A,8) or

Then as in [ example 1]]Is applied as described in (1).

Can be transformed into a + (C × 8-mod (a +24, C × 8)) or a + (C × 8-mod (a +24, C × 8)), and then applied. For example, the [ pseudo-code 14] may be executed and applied]And (4) transforming.

[ pseudo code 14]

Step 4-2 may be a procedure of determining the number C of temporary code blocks (the number of temporary CBs) using the determined a and, on the basis thereof, making CRC length + TB of the TBS a multiple of 8 and C. The purpose of using C x 8 in the above equation is to make A a multiple of 8C, but can be transformed and applied so that A is a common multiple or the least common multiple of 8 and C. Therefore, in the above equation, C × 8 may be transformed into LCM (8, C) and applied. LCM (a, b) is the least common multiple of a and b.

In the context of the present disclosure, it is,

Fig. 6 is a flowchart illustrating steps in which a base station and a terminal obtain a TBS and transmit and receive data when scheduling and transmitting downlink or uplink data. If the scheduling and data transmission procedure starts, the base station determines scheduling information in step 602 and transmits the scheduling information to the terminal through a combination of one or more of DCI, system information, mac ce, and RRC signaling in step 604. The terminal and the base station obtain the TBS from the determined scheduling information in step 606. In step 606, the TBS may be calculated using step 4-1 and step 4-2 described above. Step 4-1 and step 4-2 may be combined and performed simultaneously, or the order thereof may be changed. Thereafter, in step 608, CB partitioning and channel coding, decoding and retransmission operations are performed using the TBS, which completes data scheduling and transmission.

By comparing the code rate R with [ embodiment 1]][ example 2]][ example 3]]Or [ example 4]]May be modified to modify the MCS index (such as I) to determine the TBS by comparing specific values in_MCS) Or a method in which a parameter regarding MCS or coding rate is compared with a specific reference value, rather than directly using the coding rate for comparison.

Further, when NRE is calculated, in [ example 1]][ example 2]][ example 3]]Or [ example 4]]The case of mapping data using rate matching is described in (1), but N can be calculated using various methods_RE. For example, N may be calculated and applied by a method considering one or more of the total number of allocated symbols, the number of allocated PRBs, a synchronization signal block resource, a reference signal resource, a reserved resource, a subcarrier spacing, the number of allocated slots, a code rate, a modulation order, and the number of reference REs within a specific resource (e.g., the number of available REs within one slot or one PRB of one symbol)_RE。

[ example 5]

Embodiment 5 provides a method by which a base station and a terminal modify a calculated TBS and apply a final TBS if a specific TBS is calculated and derived when embodiment 1, embodiment 2, embodiment 3, or embodiment 4 is applied.

For example, the base station and the terminal may schedule in advance that TBSs within a specific range are not transmitted, and if TBSs within a specific range are calculated, the TBSs to be applied may be determined in advance. For example, in the process, R <1/4 and a is 3872, so the number of temporary CBs is calculated to be 2. If B is 3872, the final calculated TBS is 3800. If the finally calculated TBS is 3800, the terminal may determine the TBS to be 3840.

In another example, a method of applying a final TBS by comparing a TBS calculated in a case where the base station and the terminal know a minimum value or a maximum value of the TBS with a minimum value or a maximum value scheduled or known in advance through higher layer signaling may be used. Of TBSThe minimum value may be TBS_minAnd the maximum value of the TBS may be the TBS_max。

[ example 6]

Embodiment 6 provides a method of storing information on data received by a terminal in a soft buffer.

When transmitting downlink data, when the terminal stores received information about data in a soft buffer, the base station may know in advance how much data the terminal stores, and may accordingly notify the terminal of a start time point of the stored information. The base station may inform the terminal of the range of the stored information so as to transmit the parity part having the highest retransmission probability.

This may be indicated to the terminal by the base station through one or more of RRC signaling, MAC CE, DCI, or L1 signaling (such as SIBs).

[ example 7]

[ example 7]Provides a calculation of N_REThe method of (A), the_REIs as follows [ example 1][ example 2]][ example 3]]Or [ example 4]]When applied, the number of resource regions to which data considered for calculating the temporary TBS is mapped.

Downlink data may be transmitted using a PDSCH, which is a physical channel for downlink data transmission, and N may be obtained in consideration of one or more of the following parameters at this time_RE。

-number of PRBs allocated for data transmission and number of symbols to be transmitted

-control resource set (CORESET), where downlink control channels signaled in higher layers can be transmitted

-region to which scheduled DCI is mapped

-resource region in which Reference Signals (RSs) for data transmission are transmitted

-resource regions corresponding to reserved resources

-resources in which RS for channel measurement is transmitted

-a region in which a synchronization signal block (SS block) comprising a synchronization signal is transmitted

-timing of transmitting control information (DCI) for scheduling and timing of actual PDSCH to be transmitted

Minimum processing time for uplink and downlink data transmission and reception

Uplink data may be transmitted using a PUSCH, which is a physical channel for uplink data transmission, and at this time, N may be obtained in consideration of one or more of the following parameters_RE。

-a region signaled by higher layers in which downlink and uplink control channels can be sent

Resource region in which reference signals for data transmission are transmitted

-resource regions corresponding to reserved resources

-resource region in which Sounding Reference Signals (SRS) for channel measurement are transmitted

-a region in which a synchronization signal block comprising a synchronization signal is transmitted

Timing of transmission of control information for scheduling (uplink grant DCI) and timing of actual PUSCH to be transmitted

-whether to include and transmit HARQ-ACK information of another PDSCH, a timing of transmitting the corresponding PDSCH and an amount of HARQ-ACK information to be transmitted

-Channel State Information (CSI) reporting, reporting timing and measurement of CSI quantity

Minimum processing time for uplink and downlink data transmission and reception

For example, if HARQ-ACK of PDSCH received before a time point when DCI including a grant for uplink scheduling (uplink grant) for scheduling a corresponding PUSCH is transmitted is greater than the number of specific bits, a resource region required for transmitting the corresponding HARQ-ACK information may be selected from N obtained for PUSCH transmission_REAnd (4) excluding. On the other hand, transmission of HARQ-ACK information of a PDSCH received at or after a time point when DCI including an uplink grant for scheduling a corresponding PUSCH is transmitted may not be in useN in obtaining TBS of PUSCH_REIs considered or included in the calculation of (a). The reference time point of the PDSCH considering HARQ-ACK has been described as the time point of receiving the uplink grant, but is not limited thereto, and may be determined, for example, according to the minimum processing time for uplink data transmission, downlink data reception, and HARQ-ACK transmission. This is to ensure sufficient processing time to process the TBS of the PUSCH.

In order to perform the above-described embodiments of the present disclosure, a transmitter, a receiver, and a processor of each of a terminal and a base station are illustrated in fig. 7 and 8. The transmission method/reception method of the base station and the terminal is described as performing embodiments 1 to 7, and each of the receiver, the processor, and the transmitter of the base station and the terminal should operate according to the embodiments to implement the method.

Specifically, fig. 7 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure. As shown in fig. 7, the terminal of the present disclosure may include a terminal receiver 700, a terminal transmitter 704, and a terminal processor 702. In an embodiment of the present disclosure, the terminal receiver 700 and the terminal transmitter 704 are collectively referred to as a transceiver. The transceiver may transmit signals to or receive signals from a base station. The signals may include control information and data. To this end, the transceiver may include: an RF transmitter that up-converts and amplifies a frequency of a transmitted signal; an RF receiver which low-noise amplifies a received signal and down-converts a frequency; and so on. Also, the transceiver may receive a signal through a radio channel, output the signal to the terminal processor 702, and transmit the signal output from the terminal processor 702 through the radio channel. The terminal processor 702 may control a series of processes to cause the terminal to operate according to the above-described embodiments of the present disclosure.

Fig. 8 is a block diagram illustrating an internal structure of a base station according to an embodiment of the present disclosure. As shown in fig. 8, the base station of the present disclosure may include a base station receiver 801, a base station transmitter 805, and a base station processor 803. In an embodiment of the present disclosure, the base station receiver 801 and the base station transmitter 805 are collectively referred to as a transceiver. The transceiver may transmit and receive signals to and from the terminal. The signals may include control information and data. To this end, the transceiver comprises: an RF transmitter that up-converts and amplifies a frequency of a transmitted signal; an RF receiver which low-noise amplifies a received signal and down-converts a frequency; and so on. Also, the transceiver may receive a signal through a radio channel, output the signal to the base station processor 803, and transmit the signal output from the base station processor 803 through the radio channel. The base station processor 803 may control a series of processes to cause the base station to operate according to the above-described embodiments of the present disclosure.

Meanwhile, the embodiments of the present disclosure disclosed in the specification and the drawings have been presented to easily explain the technical contents of the present disclosure and to assist understanding of the present disclosure, and do not limit the scope of the present disclosure. That is, it is apparent to those skilled in the art to which the present disclosure pertains that various modifications can be implemented based on the technical spirit of the present disclosure. Some of the embodiments may be operated such that one or more of the embodiments are combined. For example, a base station and a terminal can operate based on a combination of [ embodiment 1] and [ embodiment 3] of the present disclosure.

Claims

1. A method of identifying a transport block size, TBS, by a terminal in a wireless communication system, the method comprising:

receiving control information for scheduling from a base station;

identifying a number of temporary information bits based on control information for scheduling;

identifying a TBS based on the control information for scheduling and the number of temporary information bits; and

decoding the received downlink data based on the identified TBS,

where TBS is a multiple of both 8 and the number of temporary code blocks CB identified based on the control information for scheduling.

2. The method of claim 1, wherein a code rate identified based on the scheduling information is equal to or less than 0.25 and the temporary information bitsIs based on

The number of temporary CBs is identified.

3. The method of claim 1, wherein in case that the code rate identified based on the scheduling information is greater than 0.25 and the number of temporary information bits is N greater than 8424, based on

The number of temporary CBs is identified.

4. The method of claim 1, wherein the number of temporary CBs is 1 in case that the number of temporary information bits is equal to or less than 8424.

5. A method of identifying a transport block size, TBS, by a base station in a wireless communication system, the method comprising:

identifying control information for scheduling;

transmitting control information for scheduling to a terminal;

downlink data is transmitted based on the identified TBS,

6. The method of claim 5, wherein in case that the code rate identified based on the scheduling information is equal to or less than 0.25 and the number of temporary information bits is N, based on

The number of temporary CBs is identified.

7. The method of claim 5, wherein in case that the code rate identified based on the scheduling information is greater than 0.25 and the number of temporary information bits is N greater than 8424, based on

The number of temporary CBs is identified.

8. The method of claim 5, wherein the number of temporary CBs is 1 in case that the number of temporary information bits is equal to or less than 8424.

9. A terminal for identifying a transport block size, TBS, in a wireless communication system, the terminal comprising:

a transceiver; and

a controller configured to perform control to receive control information for scheduling from a base station, identify a number of temporary information bits based on the control information for scheduling, identify a TBS based on the control information for scheduling and the number of temporary information bits, and decode received downlink data based on the identified TBS, the controller being connected to the transceiver,

10. The terminal of claim 9, wherein in case that the code rate identified based on the scheduling information is equal to or less than 0.25 and the number of temporary information bits is N, based on

The number of temporary CBs is identified.

11. The terminal of claim 9, wherein in case that the code rate identified based on the scheduling information is greater than 0.25 and the number of temporary information bits is N greater than 8424, based on

The number of temporary CBs is identified.

12. The terminal of claim 9, wherein the number of temporary CBs is 1 in case that the number of temporary information bits is equal to or less than 8424.

13. A base station for identifying a transport block size, TBS, in a wireless communication system, the base station comprising:

a transceiver; and

a controller configured to perform control to identify control information for scheduling, transmit the control information for scheduling to a terminal, identify a number of temporary information bits based on the control information for scheduling, identify a TBS based on the control information for scheduling and the number of temporary information bits, and transmit downlink data based on the identified TBS,

14. The base station of claim 13, wherein in case that the code rate identified based on the scheduling information is equal to or less than 0.25 and the number of temporary information bits is N, based on

The number of temporary CBs is identified.

15. The base station of claim 13, wherein in case that the code rate identified based on the scheduling information is greater than 0.25 and the number of temporary information bits is N greater than 8424, based on

The number of temporary CBs is identified, and, in case that the number of temporary information bits is equal to or less than 8424, the number of temporary CBs is1。